Port, board and/or hardware

webassembly standard build

MicroPython version

3.4.0; MicroPython v1.24.1 on 2025-03-09

Reproduction

const mp = await loadMicroPython();
await mp.runPythonAsync("import gc; gc.collect()");

Expected behaviour

In the web console, it should be no output, and the gc.collect() call succeed.

Observed behaviour

It raised an error in the web console

Aborted(Assertion failed: The call to mp_js_do_exec_async is running asynchronously. If this was intended, add the async option to the ccall/cwrap call.)

Additional Information

In the file ports/webassembly/api.js, int the runPythonAsync function, the Module.ccall missing the option { async: true }.

After adding that option to the ccall, it works as expected.

Code of Conduct

Yes, I agree